There are many applications where monitoring of a three dimensional configuration of an object can be implemented, for example monitoring of vital signs, including breathing and/or lung function of a person. In addition, monitoring of lung function can provide data which can be used to assist in determining the presence of lung disease which is a global health problem affecting millions of people. Effective medical management of lung disease requires assessment and monitoring of lung function. This is carried out largely by clinical observation or by spirometry (a technology developed in the 1930s).
There are restrictive limitations to present technologies for monitoring lung function, which fail to satisfy clinical needs; in particular, spirometry techniques require alert and co-operative patients to follow instructions whilst using an apparatus. These techniques are not suitable for use on children under 5 years old, for critically ill or unconscious patients, or for the chronically sick or elderly. Such patients often cannot be assessed or monitored fully, leaving assessment to subjective clinical observation. This leaves a subjective element to clinical decisions, for example a patient's transfer from intensive care to less resource-intensive general care or vice versa, resulting in inefficient use of resources and sub-optimal clinical management.
Other techniques for monitoring lung function require physical contact with the patient, for example requiring sensors or reflective markers to be placed on or attached to the subject. This may be medically inadvisable or impossible, for example in critical care situations such as the monitoring of a burns victim, or the measurement of lung function in premature babies.
It is an object of the invention to overcome such disadvantages.